1. Field
The present disclosure relates generally to wireless telecommunications, and more specifically, to security in wireless communications.
2. Background
Consumer demand for wireless services has led to the development of numerous wireless communication networks. One such network is based on Code-Division Multiple Access (CDMA) technology which supports wireless voice and data services using spread-spectrum processing. Spread-spectrum processing enables high quality service at low cost by efficiently using the available frequency spectrum. As a result, CDMA technology is considered by most to be the way of the future for digital wireless communications.
To provide the widest availability of CDMA technology, certain deployment strategies may be implemented. One such strategy is to introduce CDMA technology as a means for connecting to an existing network infrastructure, such as a Global System for Mobile Communications (GSM). GSM, which has become the de facto standard in Europe and Asia, represents the previous generation of digital wireless communications and utilizes narrowband Time-Division Multiple Access (TDMA) to support wireless voice and data services. By using CDMA as a means for connecting to a GSM network, or other existing networks, reduced cost may be realized because a substantial portion of the existing infrastructure may be used to support CDMA technology.
The introduction of a CDMA into to a GSM network raises a number of security issues. Currently, a GSM network establishes trust and session keys with a GSM subscriber station using a challenge/response procedure. The challenge/response procedure is based on authentication credentials and GSM algorithms stored on a removable Subscriber Identity Module (SIM) in the GSM subscriber station. The removable SIM may be installed on any GSM subscriber station, thereby eliminating the need to provision authentication credentials every time a consumer purchases a new GSM device. Many consumers of GSM products have expressed a certain level of satisfaction with this feature, and therefore, it is desirable to deploy a CDMA subscriber station that can accept a SIM from a GSM subscriber station. This will require that certain compatibility issues be addressed between a CDMA network employing a legacy protocol known as Cellular Authentication and Voice Encryption (CAVE) and a CDMA subscriber station with a GSM SIM.